What is Muscle Biopsy?
Effects of Muscle Biopsy
A muscle biopsy may be performed to identify or detect muscular disorders such as muscular dystrophy or congenital myopathy; metabolic defects of the muscle; diseases of the connective tissue and blood vessels (such as polyarteritis nodosa); and infections that affect the muscles (such as trichinosis or toxoplasmosis). A muscle biopsy may also be done to distinguish the difference between nerve and muscle disorders.
Candidates for Muscle Biopsy
A muscle biopsy is recommended for those who have unexplained weakness or muscle pain; unexplained elevations in serum creatine kinase (CK) levels; and recurrent rhabdomyolysis (the destruction or degeneration of skeletal muscle tissue).
No fasting or other special preparation is generally needed for this procedure. You may be advised though to wear loose clothing or a hospital gown so that the muscle chosen for biopsy is easily accessible.
Prior to muscle biopsy, your doctor will come up with a plan for how the muscle samples will be sent to the different labs for testing. The testing laboratories will be contacted before the biopsy is performed so that preparation of the muscle is executed properly.
The Muscle Biopsy Procedure
A muscle biopsy can be acquired while you are awake and the area being biopsied is numbed by local anesthesia. A needle biopsy may be appropriate in children and adults with chronic conditions. A needle is inserted into the muscle in this procedure. A small “plug” of tissue stays in the needle when it is detached from the muscle. This tissue is sent to a pathologist for examination. It is possible that more than one needle insertion may be required to achieve a large enough specimen for testing and examination.
Open biopsy entails a small incision through the skin and into the muscle so that a sample of muscle tissue can be taken out from the affected area. There are certain types of muscles that are not good choices for biopsy, such as muscle that has just been traumatized, or that is affected by pre-existing condition, such as nerve compression. The muscle chosen for biopsy has to be appropriate for the symptoms or suspected condition.
After the biopsy, you will stay in the treatment area for a short time for observation. Muscle soreness around the biopsied area will take place for about 1 to 2 weeks. Patients who have had the procedure describe the pain like a pulled muscle or similar to pain from a muscle strain. Your doctor may prescribe medication to alleviate pain.
The incision area should be kept clean and dry. Your doctor will advise you when the stitches should be removed (usually within 4 to 7 days). You should anticipate a small scar from the biopsy. Ask your doctor when you should return for a follow-up visit.
The risks are minimal and may include infection, bleeding of the site, brusing of the area and damage to the muscle tissue or other tissues in the area (very rare).
What happens during a muscle biopsy?
A muscle biopsy may be described as a process in which a piece of muscle tissue is removed from an organism and examined microscopically. A biopsy needle is commonly inserted into a muscle, wherein a small amount of tissue remains. Also, an “open biopsy” can be done by securing the muscle tissue through a small surgical incision.
How will the test feel?
Throughout the biopsy, there is normally minimal or no discomfort. You may feel some pressure or “tugging” sensations.The anesthetic may burn or sting when injected (before the area becomes numb). After the anesthetic wears off, the area may be sore for about a week.
Why is the test performed?
A muscle biopsy may be completed for the following reasons:
- To distinguish between neurogenic (nerve) and myopathic (primarily muscle) disorders.
- To identify specific muscular disorders such as muscular dystrophyor congenital myopathy.
- To identify metabolic defects of the muscle.
- To diagnose diseases of the connective tissue and blood vessels (such as polyarteritis nodosa).
- To diagnose infections that affect the muscles (such as trichinosis or toxoplasmosis)